Polish Prime Minister Mateusz Morawiecki has accused Belarus of committing terrorism over its role in an escalating border row between the two countries.
The EU has also accused Belarus’s leader, Alexander Lukashenko of provoking the crisis.
Lukashenko, who won a largely discredited election last year, denies claim that the country is sending people over the border in revenge for EU sanctions.
The migrants mostly from the Middle East are mainly young men but there are also women and children.